Year 10 Paper 1: Cells and Body Systems
Covers cell structure and transport, cell division and stem cells, digestion and the circulatory system, pathogens and communicable disease, and the body's defence systems and how disease is treated.
Year 10 here means a typical teaching order, not a syllabus rule. No exam board defines what belongs to Year 10, and schools sequence the course differently. Check it against your own scheme of work before using it to decide what a class has covered.
Questions
Question 1 [2 marks]
Digestion and the Circulatory System
State the function of the stomach in digestion, and state two things the stomach does to food.
Question 2 [3 marks]
Cell Structure and Transport
A student places a potato chip into a beaker of distilled water for 24 hours.
Predict what will happen to the mass of the potato chip, and explain your answer in terms of osmosis.
Question 3 [2 marks]
Human Defence Systems and Treating Disease
State what an antibiotic is, and state what type of pathogen antibiotics are effective against.
Question 4 [3 marks]
Cell Structure and Transport
Scientists can use a light microscope or an electron microscope to view cells.
State three differences between a light microscope and an electron microscope.
Question 5 [3 marks]
Cell Division and Stem Cells
In humans, most cells differentiate at an early stage of development and lose the ability to change into a different type of cell.
Describe how differentiation in plants is different from this.
Question 6 [2 marks]
Pathogens and Communicable Disease
State two differences between a virus and a bacterium.
Question 7 [5 marks]
Human Defence Systems and Treating Disease
In a trial, 3% of 2000 vaccinated people caught a disease, compared with 15% of 2000 unvaccinated people.
Calculate the number of people who caught the disease in each group, and calculate the vaccine's efficacy using efficacy (%) = (1 - (rate in vaccinated group / rate in unvaccinated group)) x 100.
Question 8 [5 marks]
Cell Structure and Transport
In an osmosis investigation, a potato chip had a mass of 4.20 g before being placed in a concentrated sugar solution for 24 hours. After 24 hours, its mass was 3.57 g.
Calculate the percentage change in mass of the potato chip, and state whether this change indicates the potato chip lost or gained water.
Question 9 [5 marks]
Cell Division and Stem Cells
A single cell divides by mitosis, and the resulting population doubles every 30 minutes.
Calculate how many complete divisions are needed for the population to first exceed 500 cells, starting from 1 cell, and calculate the total time in minutes this would take.
Question 10 [5 marks]
Cell Structure and Transport
A row of 40 root hair cells absorbs a total of 0.008 mm^3 of water by osmosis in one minute.
Calculate the mean volume of water absorbed by one root hair cell per minute, and calculate how many minutes it would take one root hair cell to absorb 0.0006 mm^3 of water at this rate.
Question 11 [5 marks]
Pathogens and Communicable Disease
At the start of an outbreak, one person is infected. Each infected person then infects 3 new people before recovering, and this repeats for further rounds of infection.
Calculate the total number of people who have been infected in total after 3 further rounds of infection beyond the original case.
Model solutions
| Question 1[2 marks] | |
|---|---|
| Answer or working | Marks |
| the stomach digests protein (using the enzyme protease/pepsin) | B1 |
| the stomach churns/mixes food with digestive juices, and produces hydrochloric acid, which kills bacteria in the food and gives the right pH for protease to work | B1 |
| Final answer: The stomach digests protein (using protease) and churns food with acid, which kills bacteria and gives the right pH for the enzyme to work | |
| Question 2[3 marks] | |
|---|---|
| Answer or working | Marks |
| the mass of the potato chip will increase | B1 |
| distilled water has a higher (more dilute) water concentration than the potato cells' cytoplasm | B1 |
| water moves into the potato cells by osmosis, down the water concentration gradient, increasing the mass | B1 |
| Final answer: The mass increases, because distilled water has a higher water concentration than the cells, so water moves into the potato cells by osmosis | |
| Question 3[2 marks] | |
|---|---|
| Answer or working | Marks |
| an antibiotic is a medicine/drug that kills bacteria (or prevents their growth) inside the body | B1 |
| antibiotics are effective against bacterial pathogens (not viruses) | B1 |
| Final answer: An antibiotic kills bacteria (or stops them growing) inside the body; antibiotics are effective against bacteria, not viruses | |
| Question 4[3 marks] | |
|---|---|
| Answer or working | Marks |
| an electron microscope has a much higher magnification than a light microscope | B1 |
| an electron microscope has a much higher resolution (can distinguish two points that are closer together) than a light microscope | B1 |
| an electron microscope is much more expensive and requires the sample to be in a vacuum, whereas a light microscope is cheaper and can view living samples | B1 |
| Final answer: Electron microscopes have much higher magnification and resolution than light microscopes, but are far more expensive and cannot view living samples | |
| Question 5[3 marks] | |
|---|---|
| Answer or working | Marks |
| many plant cells do not fully lose the ability to differentiate | B1 |
| plants retain groups of unspecialised cells called meristems (e.g. at the tips of roots and shoots) throughout life | B1 |
| cells in the meristem can differentiate into any type of plant cell, allowing plants to keep producing new specialised cells throughout their life | B1 |
| Final answer: Unlike most human cells, many plant cells keep the ability to differentiate throughout life; meristem tissue at root and shoot tips can produce any type of plant cell as the plant continues to grow | |
| Question 6[2 marks] | |
|---|---|
| Answer or working | Marks |
| viruses are much smaller than bacteria | B1 |
| viruses can only reproduce inside a host cell, whereas bacteria can reproduce independently (by simple cell division) | B1 |
| Final answer: Viruses are much smaller than bacteria, and can only reproduce inside a host cell, while bacteria can reproduce independently | |
| Question 7[5 marks] | |
|---|---|
| Answer or working | Marks |
| vaccinated cases = 3% of 2000 = 60 | M1 |
| unvaccinated cases = 15% of 2000 = 300 | M1 |
| using efficacy = (1 - (3 / 15)) x 100 | M1 |
| substituting to get (1 - 0.2) x 100 | A1 |
| 80% efficacy | A1 |
| Final answer: 60 people caught the disease in the vaccinated group and 300 in the unvaccinated group; the vaccine's efficacy is 80% | |
| Question 8[5 marks] | |
|---|---|
| Answer or working | Marks |
| finding the change in mass = 3.57 - 4.20 = -0.63 g | M1 |
| using percentage change = (change in mass / original mass) x 100 | M1 |
| substituting (-0.63 / 4.20) x 100 | M1 |
| a percentage change of -15% (a 15% decrease) | A1 |
| stating the potato chip lost water, because its mass decreased | B1independent |
| Final answer: The mass decreased by 15% (a change of -15%), showing the potato chip lost water | |
| Question 9[5 marks] | |
|---|---|
| Answer or working | Marks |
| recognising the population after n divisions = 2^n | M1 |
| testing 2^8 = 256 (below 500) | M1 |
| testing 2^9 = 512 (exceeds 500) | M1 |
| 9 divisions | A1 |
| total time = 9 x 30 = 270 minutes | B1independent |
| Final answer: 9 divisions are needed (2^9 = 512), taking a total of 270 minutes | |
| Question 10[5 marks] | |
|---|---|
| Answer or working | Marks |
| using mean volume per cell = total volume / number of cells | M1 |
| substituting 0.008 / 40 | M1 |
| 0.0002 mm^3 per cell per minute | A1 |
| using time = volume required / rate per minute | M1 |
| 0.0006 / 0.0002 = 3 minutes | A1 |
| Final answer: Mean volume absorbed = 0.0002 mm^3 per cell per minute; it would take 3 minutes to absorb 0.0006 mm^3 | |
| Question 11[5 marks] | |
|---|---|
| Answer or working | Marks |
| round 1 = 1 x 3 = 3 newly infected | M1 |
| round 2 = 3 x 3 = 9 newly infected | M1 |
| round 3 = 9 x 3 = 27 newly infected | M1 |
| the total number infected = 1 + 3 + 9 + 27 = 40 | A1 |
| identifying this pattern as exponential growth, which is why an outbreak can spread rapidly if unchecked | B1independent |
| Final answer: 40 people in total have been infected after 3 further rounds; this is an example of exponential growth | |